Bone Chips in the Knee (Osteochondritis Dissecans)

Osteochondritis dissecans is a knee problem caused by an injury to the bones or cartilage of the knee joint. The cartilage covering the femur (thighbone) or patella (kneecap) is usually affected. (Cartilage is the tissue that lines and cushions the surface of the joints.) Fragments or chips of bone or cartilage may come loose and float around in the knee joint.

Other terms for this condition are chondral fracture and osteochondral fracture. The fragments may also be called loose bodies or a joint mouse.

What is the cause?

The chips usually result from a knee injury that caused a piece of bone or cartilage to be chipped off the end of the thighbone or the back of the kneecap. It could happen after one serious injury to the knee or after repeated minor injuries. A problem with the blood supply to the bone may be part of the cause.

What are the symptoms?

Symptoms may include:

Your knee may lock up from time to time.

You may have bulges on the surface of your knee.

Sometimes you may feel the chips on the surface of your knee.

Your knee is swollen and painful.

You may not be able to fully bend or straighten your knee.

How is it diagnosed?

Your healthcare provider will examine you and ask about your symptoms, activities, and medical history. Tests may include:

X-rays of the knee

MRI, which uses a strong magnetic field and radio waves to show detailed pictures of the knee

How is it treated?

You will need to rest your knee and avoid activities that cause pain until the symptoms are gone. This may take several weeks.

Sometimes surgery is needed to remove the fragments and repair the surface of the thighbone or kneecap.

How can I take care of myself?

To keep swelling down and help relieve pain:

Put an ice pack, gel pack, or package of frozen vegetables wrapped in a cloth on the painful area every 3 to 4 hours for up to 20 minutes at a time.

Take an anti-inflammatory medicine, such as ibuprofen, or other medicine as directed by your provider. Nonsteroidal anti-inflammatory medicines (NSAIDs), such as ibuprofen, may cause stomach bleeding and other problems. These risks increase with age. Read the label and take as directed. Unless recommended by your healthcare provider, you should not take this medicine for more than 10 days.

You may need to change your sport or activity to one that does not make your condition worse. For example, you may need to bicycle or swim instead of run. You may also need to rest if your knee is swollen and painful.

Follow your healthcare provider's instructions. Ask your provider:

How and when you will hear your test results

How long it will take to recover

What activities you should avoid and when you can return to your normal activities

How to take care of yourself at home

What symptoms or problems you should watch for and what to do if you have them

Make sure you know when you should come back for a checkup.

How can I help prevent bone chips in the knee?

Bone chips are usually caused by injuries to the knee that are not easily prevented.